Cardiovascular Involvement and Its Association with Disease Severity and Recovery in SARS-CoV-2 Associated Multisystem Inflammatory Syndrome in Children.

Abstract

Background: Multisystem inflammatory syndrome in children (MIS-C) is a severe clinical entity emerging after severe acute respiratory syndrome coronavirus 2 infection, often characterized by cardiovascular involvement. This study aimed to evaluate the frequency and spectrum of cardiovascular involvement in children with MIS-C and to assess its association with clinical severity, biomarker profiles, and recovery outcomes.

Methods: This study included 54 children diagnosed with MIS-C between June 2020 and December 2023. Clinical features, laboratory parameters, electrocardiographic and echocardiographic findings, treatments, and outcomes were analyzed. Clinical severity was classified as mild, moderate, or severe. Kaplan-Meier and Cox regression analyses were used to evaluate recovery trajectories and identify independent predictors.

Results: Cardiovascular involvement was detected in 37% of patients. The most common findings were mitral regurgitation (50%), left ventricular dysfunction (20.4%), and pericardial effusion (18.5%). Patients with cardiovascular involvement were older and more likely to present with dyspnea, chest pain, tachycardia, tachypnea, and hypotension (all p < 0.01). They exhibited significantly higher C-reactive protein (CRP), interleukin-6 (IL-6), B-type natriuretic peptide (BNP), urea, and creatinine levels, and lower lymphocyte counts (p < 0.05). Moderate-to-severe cases showed markedly higher rates of left ventricular dysfunction (44%), mitral regurgitation (100%), pericardial effusion (36%), arrhythmias (16%), hypotension (44%), and inotropic requirement (44%) compared with mild cases (all p < 0.01). Recovery was significantly delayed in patients with cardiovascular involvement (median 12.5 vs. 8.0 days; p = 0.008) and in moderate-to-severe cases (14.0 vs. 7.5 days; p < 0.01). In Cox regression analysis, independent predictors of delayed recovery included cardiovascular involvement (HR: 0.48), CRP > 200 mg/L (HR: 0.52), lymphocyte count < 1000/µL (HR: 0.41), BNP > 10,000 ng/L (HR: 0.35), and IL-6 > 100 pg/mL (HR: 0.44).

Conclusion: Cardiovascular involvement in MIS-C is a strong marker of severe disease, heightened systemic inflammation, and prolonged recovery. Echocardiographic abnormalities, combined with elevations in CRP, IL-6, and BNP provide valuable prognostic information.